Fixture for magnetic chucks



Oct. 18, 1949.

G. w. STARN Filed Nov. 20, 1947 INVENTOR. 1 $80!) W.$fam.

Patented Oct. 18, 1949 UNITED STATES PATENT OFFICE FIXTURE FOR MAGNETIC CHUCKS Gleason W. Starn, Meadville, Pa., assignor to Starn Tool and Manufacturing Company, Meadville, Pa., a partnership consisting of Gleason W. Starn and James 0. Starn Application November 20, 1947, Serial No. 787,217

6 Claims. (Cl. 175-367) This invention relates to a magnetic fixture or jig, particularly adaptable for use with magnetic chucks for supporting work-pieces for grinding or other machine operations.

Various types of fixtures or attachments have been heretofore suggested and used for. supporting on magnetic chucks relatively small parts adapted to be ground or otherwise machined. While most of these devices were satisfactory for their intended use, they were unsatisfactory for other uses. In the first place, most of these devices were not designed so as to support workpieces having an irregular contour or a workpiece having projecting portions carried thereby. Secondly, such devices were limited as to the smallness of the size of work-piece that could be satisfactorily supported thereby. A most important disadvantage of these devices was that the work-piece first had to be squared in the device, then the device squared on the magnetic chuck in order to grind or machine any particular side of the work-piece.

Accordingly, it is the principal object of the present invention to provide an improved fixture for use with magnetic chucks which will square the work-piece both laterally and longitudinally when it is positioned in the fixture on the chuck.

It is another object of the invention to provide such a fixture which will support securely relatively small work-pieces and conveniently and securely support work-pieces having irregular contours or having projecting portions.

It is a further object of this invention to provide such a fixture for magnetic chucks which is simple and inexpensive in its construction and, at

the same time, efiicient and effective in its use.

It is a more specific object of the present invention to provide such a fixture consisting of an angle iron-like member having vertical walls containing vertically extending magnetizable portions, whereby the magnetism from the poles of a magnetic chuck may be transmitted upwardly along the walls and to the top of the fixture so as to secure the work-piece in position between the walls and/or to the top surface of the fixture.

Various other objects and advantages of this invention will be more apparent in the course of the following specification, and will be particularly pointed out in the appended claims.

In the accompanying drawings, there is shown for the purpose of illustration, an embodiment which my invention may assume in practice.

In these drawings:

Fig. 1 is a perspective front view of a fixture 5:; drawing 2 of the present invention, showing how it is used with a magnetic chuck;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1, showing how my improved fixture cooperates with the pole faces of a chuck;

Fig. 3 is a perspective rear view of my improved fixture, showing it in position on a magnetic chuck;

Fig. 4 is another perspective view of my fixture, showing the bottom thereof more in detail;

Fig. 5 is a perspective view, partly in section, showing how one form of work-piece is supported by the fixture of the present invention; and

Fig. 6 is still another perspective view, partly in section, similar to Fig. 5, showing how another form of work-piece is supported by my improved fixture.

Referring more particularly to the drawings, the improved fixture of the present invention comprises an angle iron or substantially L-shaped body member having a vertical wall 2 formed from a plurality of vertically extending plates or laminations 3. There is arranged at one end of the wall 2 integral therewith and extending outwardly therefrom at an angle of ninety degrees thereto, another vertical wall 4 also formed of a plurality of vertically extending plates or laminations 5. .Both the plates or laminations 3 and 5 of the vertical walls 2 and 4, respectively, are of a suitable magnetizable material, preferably steel, which are separated from each other by plates or laminations B of a suitable non-magetizable material, such as a non-ferrous material, preferably brass. If these plates 6 are of brass, then the steel plates and these plates 6 are preferably brazed or soldered together to form a unitary member or they may be pinned together, if de:- sired.

The upper ends of the steel plates or laminations 3 and .5 and the non-magnetizable plates or laminations 6 terminate in a common plane at the top of the fixture. In other words, the upper ends of all the plates or laminationsare flush with each other so as to provide a smooth flat continuous surface on top of the walls 2 and 4. The rear side of the steel plates or laminations 3 and laminations 6 of the wall 2 are also fiush so as to present a smooth surface but, as shown in Figs. 2, 3, and 4, the alternate steel plates .3 are undercut at I at the bottom rear side thereof for a purpose hereinafter to be described.

As more clearly shown in Figs. 2 and 4 of the the side walls of the steel plates or laminations 5 and laminations 6 of the wall 4 are also fiush so as to present a smooth surface on either side thereof, but alternate steel plates or laminations 5 are undercut, as at 8, on the bottom rear side so as to provide supporting or pole contact post portions 9 for contacting the same pole on the face of the chuck. The other steel plates or laminations 5 of the Wall 4 are undercut, as at II], on the bottom front side so as to provide supporting or pole contact post portions H. for contacting the pole of the opposite magnetic sign.

These projections 9 and I2 comprise supporting portions upon which the fixture is adapted to rest, as shown in Figs. 1 and 2. One set of projections 9 rest on one series of pole pieces in the magnetic chuck and are adapted to be energized with one magnetic sign, and the other set of projections rest on the other set of pole pieces of the chuck and are adapted to be energized by the opposite magnetic sign. In other words, the extreme bottom end portions of the plates 5 are undercut, as at 8 and I0, so as to provide staggered end portions 9 and I2 which are adapted to be positioned on opposite magnetic poles of the chuck. The bottom ends of the plates or laminations 3 and 6 of the wall 2 also are adapted to rest on the face of the chuck with adjacent steel plates disposed on poles of the opposite magnetic sign. By such an arrangement, it will be seen that adjacent plates or laminations in both the walls 2 and 4 are adapted to be energized diiferently.

The fixture of the present invention is used in the following manner. As shown in Figs. 1 and 3 of the drawings, the fixture is positioned on the top face of a magnetic chuck C with the rear side face of wall 2 positioned flush against the back rail R of the chuck with alternate supporting portions I3 of alternate steel plates 3 resting on poles of the same magnetic sign and with the supporting portions ll of the other plates resting on poles of the opposite sign. Alternate plates or laminations 3 of the wall 2 are relieved or undercut, as at I, so that these plates do not contact this back rail R so that all of the steel plates 3 will not be of the same magnetic sign when energized. By such an arrangement it will be seen that adjacent plates are always energized differently.

In placing the fixture in such position on the chuck, it will be seen that the wall 4 extends outwardly from the back rail and disposed at right angles thereto with the adjacent contact poles 9 and In of the plates 5 resting on opposite poles so that the plates are energized differently in a manner as hereinbefore explained.

The work-piece W is then positioned in the angle of the fixture between and against the walls 2 and 4 thereof, as shown in Figs. 5 and 6, and the chuck simultaneously energized so as to hold the work-piece in position thereon. No other adjustments of the fixture or work-piece are necessary and the work-piece is ready to be ground or otherwise machined. When the work-piece is positioned in the fixture in such a manner, it will be seen that it is squared in both directions or two planes, both transversely and longitudinally, so that the work-piece is squared in two planes simultaneously, and this is one of the most important aspects of the invention. If it is desired to grind or machine the face of an irregular object or one having a projecting portion such as, for example, a stud, the shank is DOS tioned in the angle between the wells withthe under side of the head resting on the top surface of the fixture at the intersection of the two walls, as shown in Fig. 6. It will be seen that such a work-piece is held securely by the fixture for any machining operation thereon. Also, due to the construction and arrangement of the fixture of the present invention, extremely small parts or work-pieces can be securely held between the walls 2 and 4 at the intersection thereof which also is a decided advantage.

As a result of my invention, it will be seen that there is provided a fixture which is adaptable for use with a relatively wide range of work-pieces so as to hold them securely while being machined. Further, the work-piece is held squarely and firmly by the fixture from the time it is positioned therein until the time it is removed therefrom, eliminating the necessity of any further adjustment for squaring the same after it is once positioned in the fixture.

While I have shown and described an embodiment which my invention may assume in practice,

it will be understood that this embodiment ismerely for the purpose of illustration and description, and that other forms may be devised within the scope of my invention as defined in the appended claims.

What I claim as my invention is:

l. A work-supporting fixture for use with a magnetic chuck comprising a body member having two vertical walls arranged angularly relative to each other, each of said walls formed of alternate magnetic and non-magnetic plates extending vertically and arranged substantially perpendicular to the respective Walls, at least part of the magnetic plates of at least one of said walls being undercut at the extreme bottom end thereof so as to provide bottom supporting end portions which are adapted to be positioned on opposite magnetic poles of the chuck whereby adjacent magnetic plates are magnetized as opposite magnetic poles when said fixture is positioned on and energized by the chuck.

2. A work-supporting fixture for use with a magnetic chuck comprising a body member having two vertical walls arranged angularly relative to each other, each of said walls formed of alternate magnetic and non-magnetic plates extending vertically and arranged substantially perpendicular to the respective walls, the extreme bottom end portions of adjacent magnetic plates of one of said walls being staggered relative to each other and alternate magnetic plates of the other wall being undercut at the extreme bottom back side thereof so that adjacent plates in each of said walls are adapted to be positioned on opposite magnetic poles of the chuck whereby adjacent magnetic plates are magnetized as opposite magnetic poles when said fixture is positioned on and energized by the chuck.

3. A work-supporting fixture for use with a magnetic chuck comprising substantially an L-shaped body member so as to provide two vertical walls arranged substantially at right angles to one another forming the legs of said L-shaped body member, each of said walls formed of alternate magnetic and non-magnetic plates extending vertically and arranged substantially perpendicular to the respective walls, the extreme bottom end portions of adjacent magnetic plates of one of said walls being staggered relative to each other and alternate magnetic plates of the other wall being undercut at the extreme bottom back side thereof so that adjacent plates in each of said walls are adaptedto be positioned on opposite magnetic poles of the chuck whereby adjacent magnetic plates are magnetized as opposite magnetic poles when said fixture is positioned on and energized by the chuck.

4. A work-supporting fixture for use with a magnetic chuck having parallel magnetic zones of opposite polarity comprising a body member having two vertical walls arranged angularly relative to each other, each of saidwalls consisting of a plurality of alternate magnetic and non-magnetic plates extending vertically and arranged substantially perpendicular to the respective walls, the extreme bottom ends of the magnetic plates of both of said walls being constructed and arranged so that adjacent plates of each of said walls are adapted to rest on opposite magnetic poles of the chuck whereby adjacent magnetic plates of each of said walls are magnetized as opposite poles when said fixture is positioned on and energized by the chuck so that a workpiece may be securely held between the walls of said fixture.

5. A work-supporting fixture for use with a magnetic chuck having parallel magnetic zones of opposite polarity comprising substantially an L-shaped body member so as to provide two vertically extending walls which form the legs thereof, each of said walls consisting of a plurality of vertically extending alternate magnetic and non-magnetic plates, the extreme bottom ends of all of the plates in one wall terminating substantially in the same plane so that the bottom ends of adjacent magnetic plates thereof are adapted to rest on opposite magnetic poles of the chuck, the extreme bottom ends of alternate magnetic plates of the other wall extending to the bottom surface of said wall and arranged so as to rest on one magnetic pole of the chuck with the other magnetic plates of said last mentioned wall extending to the bottom surface thereof and arranged so as to rest on an adjacent magnetic pole of opposite polarity of the chuck whereby adjacent magnetic plates in each of said walls are magnetized as opposite magnetic poles when said fixture is positioned on and energized by the chuck so that a work-piece may be securely held between the legs of said fixture.

6. A work-supporting fixture for use with a magnetic chuck having parallel magnetic zones of opposite polarity comprising substantially an L-shaped body member so as to provide two vertically extending walls which form the legs thereof, each of said walls consisting of a plurality of vertically extending alternate magnetic and non-magnetic plates, one of said walls adapted to extend substantially parallel to the parallel zones of the chuck with the other wall extending substantially perpendicular thereto, the extreme bottom ends of all of the magnetic plates in the second-mentioned wall terminating substantially in the same plane so that the bottom ends of adjacent plates thereof are adapted to rest on opposite magnetic plates of the chuck, the extreme bottom ends of the adjacent magnetic plates in the first mentioned wall being staggered relative to each other so that the bottom ends of said adjacent magnetic plates will rest on opposite magnetic poles of the chuck whereby adjacent magnetic plates in each of said walls are magnetized as opposite magnetic poles when said fixture is positioned on and energized by the chuck so that a work-piece may be securely held between the legs of said fixture.

' GLEASON W. STARN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,301,135 Karasick Apr. 22, 1919 1,330,558 Simmons Feb. 10, 1920 1,343,751 Simmons June 15, 1920 FOREIGN PATENTS Number Country Date 113,568 Great Britain Feb. 28, 1 918 

